1. Field of the Invention
The present invention relates to a printed wiring board design aiding apparatus, a printed wiring board design aiding method, and a printed wiring board design aiding program that calculate a deflection quantity and a warpage quantity of a printed wiring board.
2. Description of Related Art
Heretofore, a wiring pattern design in a printed wiring board uses an automatic tool and the like on the basis of a design rule (a width, a thickness, an interval and the like of a wiring) and is manufactured without considering conditions of material selection, manufacturing process and the like. Therefore, a deflection (displacement) and the like effected by influence of a temperature change in a temperature processing step might be sometimes increased after the printed wiring board has been completed. In such a case, it is repeated to again manufacture the printed wiring board by altering the design.
As a conventional technique which can determine a position of a reinforcing section of a printed wiring board by a simple and more rational method, a technique is known comprising a step of embedding a dummy material lowered in rigidity in a groove section of a multi-surface printed wiring board as compared with its peripheral portion, a step of obtaining a stress or deformation quantity distribution of the groove section by performing a warpage and deformation simulation to the multi-surface printed wiring board embedding a dummy material, and a step of specifying a high stress portion or a high deformation quantity portion in the groove section on the basis of the obtained stress or deformation quantity distribution (e.g., Patent Document 1: Jpn. Pat. Appln. Laid-Open Publication No. 10-93206).
However, since a problem becomes clear after a printed wiring board has been manufactured in the above-mentioned conventional technique, a repetition of a cycle of designing and manufacturing the printed wiring board has been increased to prolong a developing period and to increase its cost. If a problem considered in advance in the case that a displacement is increased is intended to be predicted by using a three-dimensional analysis and the like, a huge number of factors have been brought about in the conventional analysis method and, therefore there is raised a problem that the analysis becomes complicated, requiring work and time cost.
Even in the above-mentioned patent document 1, the displacement of such a complicated printed wiring board due to temperature change cannot be easily predicted.